


One Heated Baker

by Sepulchral_Sentience (orphan_account)



Series: Undertum But Not with Sans or Papyrus Because Others Deserve Love [2]
Category: Undertale (Video Game), undertum
Genre: Bondage, F/M, Feeding Kink, Force-Feeding, Gen, Instant Weight Gain, Weight Gain, Weight Gain Kink
Language: English
Status: Completed
Published: 2021-01-10
Updated: 2021-01-10
Packaged: 2021-03-14 14:53:57
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,828
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28672551
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/Sepulchral_Sentience
Summary: Grillby bites off more than he can chew when he visits a certain spider's bakery to satisfy his monthly charge of magic.
Relationships: Grillby & Muffet (Undertale)
Series: Undertum But Not with Sans or Papyrus Because Others Deserve Love [2]
Series URL: https://archiveofourown.org/series/2101365
Kudos: 23





	One Heated Baker

* * *

Probably the worst part about Grillby's heat season was the need to satisfy the hungry yearning in his gut. The no-nonsense bartender of Snowdin wasn't one to typically flaunt or gossip about his personal life, unlike the customers that typically crowded his restaurant 24/7.

All except Sans he refrained from speaking to, and the skeleton, in turn, seemed to have a line of respect amidst his jokey, smooth-talking self. Despite this, Grillby enjoyed speaking with him and hearing those horrendous puns he liked to fling around.

The period of itching heat, according to the elemental monster, was a regular thing since he was made of luminous magic that needed raw energy. Though most monsters could relate to being composed of such properties, Grillby's was more.. well, needy to say the least. Being composed of _fire_ of course required him to continually burn, and once every few months, his magic needed an extra 'boost'.

The symptoms were Grillby's main concern since every time the heat season would approach, he didn't know how hard they would hit.

One evening near closing time, on the month of which the cycle would begin, he spoke to Sans about this, since the skeleton had been informed about it during their casual, quiet talks.

Well, quiet as Sans could be.

"Gee Grillbz, worried about your period again?"

Grillby let out an annoyed huff of smoke from where he leaned over the counter on his elbows. "Honestly, Sans, I'd think you'd be a little more considerate."

The skeleton flicked his blue eyes from where they were situated on a bottle of ketchup, just out of arm's reach. One of his eyes lit up as he tried to levitate it over, only to have the fireman pluck it up and place it beneath the counter with a pointed look.

Sans pouted, kicking his slippers beneath the stool. "Well, damn. C'mon, do you have a _bone_ to pick with me? Are things gonna get _heated?"_

The flat look Grillby sent him made him chuckle nervously. "Alright, fine, ya got me. What are you so worried about? If it's just your body cleaning stuff out.."

"Here's the thing," the fireman laid out his hands, "this is rare and the effects are hardly... bad as I fear this time around."

"Doesn't your niece get it?" Sans asked, raising a brow.

"She does," Grillby rubbed his neck, "But it's natural for a young elemental to indulge in the needs their body craves."

"That's all you're worried about?" the skeleton crowed, slapping the counter, "Grillby, get real! You're worried about overeating because you're getting the munchies more than usual?"

The bartender came back down on his elbows, his mass of fire flaring a hot cyan out of chagrin. "Well.. yes, but-"

"You really need to live a little," Sans chortled, "even if you're not a moody teen. C'mon, tell me ya don't have a sweet tooth or guilty pleasure."

Grillby stayed silent, pursing his lips. Guilty pleasures? He had a few... Hardly the appropriate ones diet-wise. Still, maybe he was overreacting for something that hadn't even happened yet.

"You're right," he admitted, "I suppose I should just _chill."_

"Don't _flame_ yourself, 'cause now you're _cooking,_ " Sans guffawed.

"Get out," Grillby waved his hand in a shooing motion, though his usual expressionless face glimmered with amusement, "Be safe out there."

"Mind if I take something to go?" the skeleton asked, darting his eyes to the counter.

The bartender sighed. A moment later, a bottle of ketchup skid across the wood and into Sans's bony hand. He grinned, stepping from the stool and giving a two-fingered salute. 

"Thanks, Grillbz. Don't party too hard."

Grillby raised his brows and folded his arms, shaking his head. All was silent after the skeleton left, and he took the liberty of closing up. 

However, before he would call it a night, Grillby decided to take a walk in the Hotlands, to relieve some stress from the conversations. Nothing like a brisk walk in the sauna-like atmosphere...

~

What made Grillby fearful of anything would be its unpredictability. Which of course, were two things: one, walking alone near the dreaded spider woman's cave, and two, his heat cycle fully kicking in once he stepped foot into the arid Hotlands.

The bakery owner was notorious for getting what she wanted, if not in the most discreet, cunning way as possible. Behind the mauve bows and frilly apron was a money-hungry and quite possibly bloodthirsty creature. 

But, Grillby somehow managed to completely override those thoughts, steered by the will of getting something sweet to tame the particular cravings that began to nag at him.

Upon entering the dimly lit cavern, violet hues shimmering against the stone, a distinct chittering could be heard above. As he passed by billboards and posters plastered with sugary promise, the chittering then turned into an awed sort of gasping as he stopped near the check-out table, adjusting his trench coat collar.

A figure descended on a thread, her hair bouncing in two perfect pigtails. A grin split Muffet's fanged lips. "Why, hello Mr. Grillby! What brings you to my humble bake sale?"

"Just thought I'd drop by," the fireman answered coolly, feeling old rivalry from competing businesses sneak into his tone. He kept it casual and polite as best he could. "Is it true you're having a sale?"

"I see you want to help the noble cause?" Muffet questioned back, delicately balancing and landing on her feet. Her four hands clasped together in hopeful anticipation. A mischievous spark lit up her eight eyes.

"Something like that."

"Well, step up, make a choice."

"Mm.." Browsing the overpriced items on a neat little board, he inquired, "What do you recommend?"

"What do you like?"

Grillby thought for a moment. "I'm sure it wouldn't matter, sweets are sweets."

"Excuse me?" Muffet gave a small gasp, taken aback. "You mean to tell me my sweets are just like any other sweet? There's nothing unique about them?"

"Wh-?" Grillby became equally shocked, his fire releasing worried embers. A strange heat flooded his face, tinting it a cyan hue. "No, not at all. I meant-"

"I know exactly what you meant," the spider girl hissed, slamming six hands on her check-out table and squaring up to the tall elemental, who surprisingly cowered a little. "You think you're such a fancy gentleman who sells the best product? Tsk tsk, Mr. Grillby, I can show you what real baking tastes like!"

She then seemed to compose herself, flattening her apron and fixing the elemental a calculating, yet haughty glare through the slits of her multiple eyes. 

Grillby prayed his apologies had pacified her until she announced, "Babies, it's time we showed this gasoline-gulper a true taste of Muffet's pride and joy."

Before the fireman could blink, webbing snatched him up by the limbs and torso. It was of a sturdier consistency to hoist him up; much to his dismay _fireproof_ when his enraged flames went sky-high. "Wh-How dare you! Let me go this instant! I didn't mean to sound-"

"Oh hush." The spider-girl would have none of Grillby's frantic words. She had pulled him up into the vast ceiling of her cave with a maze of web surrounding them and a faint, velvety violet light shining down.

The bartender struggled and bristled in an inferno of bewilderment. He could have easily taken the smaller monster down- he doubted any could withstand his plumes of bright orange, now turning blue from the utter rage he was in. 

But his fit was short-lived as something was crammed into his mouth that was about to spew more demands of being set free.

Grillby paused, realizing it was a slice of cake prohibiting any sentences from coming out. At the tip of swirled frosting sat a spider as big as a golf ball, and the fireman nearly spat the thing out if the flavor didn't stick to his palate in an entrancing state. 

His starving magic clung to the sweet taste while his quickly fading mind would be more than happy to cook every spider to a twitching crisp.

Seeing Grillby's slight apprehension about the cake, Muffet tittered and plucked up the fuzzy arachnid. "Relax dear, it's almond and not one of my own. Also, I hear it's a rather famous bartender's favorite kind of flavor?"

Grillby didn't respond since the slice was halfway down his smoking gullet. Once it was eaten and he managed to disintegrate the thick crumbs with a molten tongue, he croaked, " _S-She-demon_."

"Ahuhu~" Instead of reverting to her hostile mode, Muffet seemed pleased. Her fingers daintily danced down Grillby's forehead and placed a light boop on his scalding lips. "By the looks of things, I'd say someone enjoyed their piece of almond cake. Is that right, dearest?"

It was too fantastical to describe, the elemental realized. Such a balance between flour and sugar he couldn't fathom the spider could make in a way that would put his small menu of dessert options to shame. 

Of course, he'd never admit that fact out loud. Not ever submit to the wonderfully sweet taste of the devil spiderwoman's culinary talent-

Another slice stuffed itself into his mouth.

Enraptured once again, Grillby could only glare at Muffet as she giggled. "We'll have you become our biggest fan. How's the sound of that, hm?"

After the bartender got the heavenly rich piece down and processed, he never got to answer in the sour manner he so craved to do. There was another nutty slice- a whole cake he realized- waiting to be forced into his open mouth. 

And a pan of brownies. 

And a tray of frosted cookies. 

A whole array of treats he was sure Sans would have no trouble scarfing down greedily.

However, these were packed into him to prove just how good of a baker Muffet claimed she was. And Grillby's ravenous magic couldn't protest, nor disagree.

Internally, as his stomach bulged uncomfortably against his belt and vest, he knew this was more than enough of what his body truly wanted. He just didn't expect to be gorged in such a manner. A week or two could be devoted to indulging and replenishing the charge in his veins... 

A whole sitting might as well be his death, and who knew how much Muffet was planning on 'showing off'?

By the looks of things, it would be more than he could chew.

Two cupcakes into a fresh box of pastel-swirled delights, Grillby was visibly struggling to keep up. He turned his head away from an outstretched fourth limb clutching sugary doom and couldn't keep the soft groan from slipping out. 

The elemental wished to massage the stretching skin beneath his clothes, but such an informal thought was enough to make him want to retch up all the forced-down sweets.

"Aw, tummy ache?" Muffet inquired with fake sympathy. A few sticky strands of webbing tugged off Grillby's trench coat, although it wasn't his main source of restriction.

Given a chance between mouthfuls, the fire monster rested against his bonds and panted, "N-Nf.. you've proven.. Enough.. R-release me."

"Can't do that, deary no, no." Muffet hardly regarded his pathetic plea, silencing any other with a cupcake and sweet-and-sinister smile. "You're _mine_ now. Why I even think this would be the perfect time for you to tell me what you think of my new line of desserts!"

Grillby frantically flickered and shook his alight head. Alas, his disagreement was muffled. He could hardly believe how sour this predicament had turned. Had he really come off as rude? Of course not. This spider-demon just liked preying on monsters caught off-guard. 

Ohh, what a day. The elemental knew it would only worsen, just like his gut pain.

A whole three boxes of cupcakes later, Grillby was stuffed tight and round as a drum. Muffet admired her handiwork, drawing two pairs of hands along her victim's tortuously swollen stomach that was just shy of popping his vest and pant buttons.

"That belt must be cutting you in half, hm?" she remarked, patting Grillby's warm, glowing underbelly that was indeed overlapping the leather as it peeked out from his uniform. The swirling orange hue of digesting goodies and magic it was radiating looked like magma brewing in a volcano.

By god, it hurt to even _breathe._ In response to the spider woman's fingers being nosy and teasing, Grillby flared his flames. The crackle of embers momentarily spooked Muffet, who yelped and retracted. 

Above, the little spiders and voices gave squeaks and minuscule shouts of fear.

"T-touch-hf- me again.. I-hng- _dare_ you.." the fireman fizzled and snapped. His hardly-seen eyes behind his glasses locked with all eight of Muffet's, which narrowed and reflected his challenging aura.

"Getting _feisty,_ are we?" she muttered. The corner of those fangs upturned in a smirk. "Well then, let's put out that raging spiciness. Babies~! Bring Mama a funnel and the _goods~!_ "

At their mistress's call, a curtain of spiderlings descended. They seemed to immediately understand her requests, for in their clutches was a funnel and different containers of liquids.

Grillby's heart dropped into his packed paunch, and his lips parted. Oh, this wasn't good.

"Open up!" Muffet took the opportunity to shove the tube of the funnel into the elemental's ajar mouth. "If you melt my good utensil, I have other methods of doing this that I'm sure you'd never want to experience."

Obeying at this point and magic somehow aching for more, Grillby had no other choice but to let the first item be poured into his awaiting stomach. 

Rich cream flowed down upon the many layers of spongy breading and icing. Grillby mentally cursed in horror as he felt it seep into the cakey concoction, causing his breadbasket to rise like it was baking and strain his vest.

Muffet let the funnel be supported by another thread of web as she picked out another item and rambled on about its recipe and whatnot. 

"Ooh, how do you like your milk Mr. Grillby? Warm? Good! Because here it comes! Very good thing I laced this with an absorbing potion! You won't be as full now when you eat, you'll instantly convert it into weight!" She paused her revealing, taking in the swelling sight.

Grillby chugged on the drink helplessly as his engorged stomach gurgled, and the exposed spaces between his vest buttons separated into tight diamond shapes. His belt too, clung around like a rubber band on a balloon, squeezing the daylights out of him. 

The first one to depart was a bottom button, and quickly to pursue was the next in line. Then, as Muffet dumped into the funnel a rather thick ooze of syrup, that was enough to sever the leather.

With a sharp metal snap, the fireman could finally breathe somewhat. Unfortunately, it only made the frothing liquid inside him surge out a little faster, and now, seek other places to infiltrate and _inflate_.

Grillby let out a panicked groan between gulps, wishing terribly for it all to be over. His fattening parts consisted of his middle, heavy and sloshy, his chest which was growing softer by the minute, and- by the Underground- his _bottom half._

Slack seams stood no chances against his plushy thighs and behind pushing against them. Shredding and fastening like a second skin, his bartender uniform couldn't withstand the enchanted drink's effects as he billowed and bloated unimaginably.

Grillby didn't know how in the world the webbing didn't break from how large he was getting. He didn't even know he _could_ get this big! The only bit of webbing that did was around his pillowy arms, and he feebly held his sides as they widened out with liquid richness.

At last, Muffet emptied the last container, leaning far over the expanse of his girth. She pulled the funnel from the far-from-full fireman's mouth, cooing, "Feels better, doesn't it? Have you learned your lesson?"

Poor Grillby moaned and panted, barely able to cup his mouth as he let out an unceremonious belch Sans would have congratulated him on. The weight that he had accumulated was albeit not as painful as before thanks to the secret potion and beyond, but.. oh goodness, this was beyond even Sans's limits! 

The bartender nearly forgot that the sugar would soon boost him with new magic. When he recalled his heat cycle that drove him here in the first place, he almost thanked Muffet if he hadn't been throbbing a million shades of infuriated blue. 

He'd make sure that once the opportunity hit, he'd set the place on fire and turn the mastermind behind this horrible plot into a charcoal heap. 

"You..-urp!- w-witch," the fireman half-hiccuped-half-growled out. "Damn y-you and your sweets."

Muffet merely laughed as her new nickname implied, rubbing her many hands along Grillby's balmy skin burning a translucent orange. "Naturally, deary. I take it that's the closest I'll get to a decent compliment for my baking. You'll get my bill, ahuhuhu~!"


End file.
